[conspire] Last Year's Supercomputer

[Mark S Bilk]

In-Reply-To: <20030609074100.GS29461 at linuxmafia.com>; from rick at linuxmafia.com on Mon, Jun 09, 2003 at 12:41:01AM -0700
Organization: http://www.cosmicpenguin.com

On Mon, Jun 09, 2003 at 12:41:01AM -0700, Rick Moen wrote:
>Mark, I was still a little groggy, when I wrote that post (and in a
>hurry to get out the door.  Commenting on my own post:
>
>> You know, they're been offering some good deals.  Bear in mind that it's
>> difficult to even approach whole-system pricing when assembling a system
>> from parts, though.  I like to do the latter because I can control parts 
>> selection and quality, but am aware there's a substantial premium.
>
>What I mean is:  If you were quoting Fry's pricing for a pile of
>individual components, please be aware that you can typically do a
>_whole_ lot better on pricing if you buy one of their assembled systems.
>Sometimes, the latter work out better even if you end up having to
>extract, discard, and replace a few crappy components.

I'll keep that in mind.  I'm now leaning toward an nForce2 
motherboard and an Athlon XP 2500+ or 2800+ CPU, which has
a 333MHz bus instead of 266, and 512KB of L2 cache instead
of 256K.

I already have a lot of components that will transfer over,
so paying for crappy ones might even the score.

>> Well, the good news is that Linux, like Unixes generally, will tell you
>> very clearly that you have a RAM-defect problem through continual SIG 11
>> errors and segfaults.  If you know what that means, then you use
>> memtest86 to confirm your suspicions, and then you swap out the
>> offending stick.  Because Linux has this (sort of) built-in RAM-defect
>> alarm system, I don't consider it cost-effective for that OS.
>
>By "it", I meant ECC:  ECC is mostly a crutch for poor bastards stuck on
>NT, who need it to warn them that their data are turning to mush.
>You're on Linux, so save your money:  Put the RAM through initial
>burn-in on memtest86 for at least 24 hours, and you'll be fine.  If you
>ever start getting SIG11s or frequent segfaults, that's Linux telling
>you to wake up because you've developed a RAM (or CPU) problem.

Good; that's comforting.

>But that experience confirmed me in my prejudice that a cool CPU
>(like a cool system generally) is much, much, much to be preferred over 
>one that runs hot and needs heroic measures like huge amounts of forced
>air flow to stave off disaster.  Those other ones may be faster -- but 
>usually (for most machine roles) don't even manifest that speed in ways
>you especially care about.

I may be getting into multimedia, and I also want very fast 
rendering of web pages, pdf files, and other such stuff that's
currently frustrating.

AMD lists the max power dissipation of their CPUs in the 2500+
range as 70 watts.  If an Intel CPU is half that, the difference
is 35 watts, which isn't all that much as far as causing discomfort
to a person nearby (my computer sort of has to sit up on my desk
next to me).

Is the fan/heatsink that comes with the boxed Athlon XP a good one?

>You wrote:
>
>>  21 Tekram DC-315U Ultra-SCSI/SCSI-2 controller PCI card
>>     with internal and external connectors.
>
>That's certainly inexpensive.  I'm a little unclear what you're using it
>for, since you didn't include any SCSI components -- nor any hard drives
>of any sort, actually.  

Exabyte tape; it's plenty fast for that.

>So:  I have no idea _why_ you're buying a SCSI card for a system with no
>SCSI devices listed -- but I'd pay $70 more for something like the
>DC-390U2B instead of sinking $21 into something like the DC-315U, whose
>drawbacks and limitations over the long term would just frustrate me.
>
>I'd get a long-term good SCSI card even if my only current use for it
>were driving a flat-bed scanner, just so it would work well in other
>roles, later.

Good idea, but can't afford it.

>I'm guessing that you're intending to carry forward your hard drive(s),
>video card, keyboard, mouse, and monitor.  Fair enough.  I would, too.

Yes.  Thanks for your help!  And also to the others who wrote.  I've 
been making major changes due to this advice!

  Mark